There is an important hidden lesson for climate activists in the vast downgrade of recoverable oil resources now thought to be available from California's Monterey Shale. Almost all climate activists have rejected any talk that the world's oil, natural gas and even coal supplies are nearing plateaus and possibly peaks in their production. That's because they fear that such talk will make the public and policymakers believe that climate change will be less of a problem as a result or no problem at all.

Any yet, for obvious reasons climate activists rejoiced when the Monterey downgrade was announced. But this only served to highlight the fact that climate activists have lost control of the public narrative on energy and can only steal it back by including constraints on fossil fuel supply as part of their story.

In fact, climate activists have been content to accept fossil fuel industry claims--the two parties agree on little else--that we have vast resources of economically recoverable fossil fuels, the rate of production of which will continue to grow for decades--unless, of course, climate activists stop this trend. This stance makes for an heroic narrative, but misses what is actually happening in the minds of the public and policymakers, minds which must be won over in order to address climate change effectively.

Let me explain.

The hype surrounding the now vastly downgraded treasure trove of oil once thought to be recoverable from California's Monterey Shale acted as a siren song on a state long devoted to energy innovation and a gradual transition away from fossil fuels. After all, California is the only state that has a climate change policy that will force businesses, localities and households to reduce their greenhouse gas emissions drastically and thus reduce their fossil fuel use drastically.

Sirens, mythological beings who are part woman and part bird, are said to send sailors to their demise through irresistible singing that lures them to crash on rocks they would normally attempt to avoid. It turns out that the thought of large amounts of readily available hydrocarbons under California has had a similar effect on the state's sustainability-minded population.

Of course, large deposits of readily available oil would have spelled large amounts of money, both as income to individual Californians and as tax revenues to various California governments. And, such oil deposits would have also spelled large contributions to California politicians in whose hands the fate of drilling and production regulations lie.

But the siren song of oil in California ended abruptly when the U.S. Energy Information Administration (EIA) announced that, based on new information, the Monterey Shale actually contained 96 percent less recoverable oil than previously thought. Climate and anti-fracking activists were overjoyed. This vast resource in all likelihood will not be heavily exploited, and most of the oil in it left unburned. (Yes, the oil is still down there. The EIA just doesn't think anyone will be able to recover it profitably using known technology.)

Since the 2008 spike in oil prices, the oil industry had been looking for a way to convince the public and policymakers not to abandon fossil fuels in favor of renewable, sustainable alternatives. When the so-called "revolution" in hydraulic fracking provided a temporary bump in U.S. oil and natural gas production, the industry found its message. With rising production America would now become a new oil and gas superpower, ending its fossil fuel imports and even exporting some of its largesse to the rest of the world. (This claim is proving to be a wild exaggeration, but that doesn't keep it from being effective.)

The other purpose of this narrative--which has been heavily touted in the media--is to change the conversation from climate change to rising fossil fuel supplies and the benefits that such supplies will bestow on America and ultimately the world.

So far, the oil industry's strategy has worked famously. The media and the public are abuzz with the message of renewed American strength and prosperity resulting from fracked oil and natural gas. Yes, there are stories about the environmental and health hazards of this process. But, the vast majority of Americans remain far away from and therefore unaffected by these hazards.

As long as the news is about the success of fracking and even about its hazards, the public will fixate on the question of how to obtain the country's supposed newfound abundance safely rather than on the unfolding horror of climate change.

But, there are, in fact, two justifiable reasons for us to move away from burning fossil fuels: climate change and supply constraints. We need to transition to other energy sources because fossil fuels are accelerating climate change AND because we simply do not know when these fuels will decline in their production rates. Current evidence suggests that the risks of such a decline are mounting.

Unless climate activists embrace this dual message, they will be ceding the argument to the fossil fuel industry. With its huge financial resources the industry will continue largely unopposed to spout the abundance narrative which experience now tells us trumps discussion of climate change.

Read for yourself any glowing account of America's new oil and gas abundance and you will ALMOST NEVER see any mention of climate change.

But, the Monterey Shale downgrade is not an isolated incident. It's part of a pattern of downgrades that are making expectations about the trajectory of oil and natural gas production in the United States more realistic.

Moreover, world prices for oil when measured using the average daily price have hovered at or near record levels for the past three years despite the shale boom in America. Worldwide oil supplies have barely grown since 2005, even as China, India and the rest of Asia have increased their demand. (That demand has been in large part accommodated by declines in U.S. and European oil use resulting from sluggish economies and changes in driving habits due to declining incomes.)

The evidence is compelling that the risks to fossil fuel supplies are rising and that the world's and the nation's reliance on them is a dangerous dependency. That combined with the national security implications suggests that the United States (which remains a huge importer of oil) and all other energy importing nations are far better off moving toward energy supplies that are entirely homegrown and can be relied upon indefinitely.

This is a forceful argument when combined with concerns about climate change. And it is a necessary addition to the arsenal of climate change activists if they expect to refocus America and the world on the imperative of addressing climate change effectively.